The invention relates to a drive slip control system including a slippage control circuit which forms a reference value that corresponds to the vehicle speed from the wheel speed signals of the non-driven wheels. The sensor signals of the driven wheels are compared to this reference value, and if the sensor signal of at least one of the driven wheels exceeds the reference value by a prescribed slippage, a control signal which depends on the reference value is generated.
When drive slip control systems are used, it is known to derive from the non-driven wheels a reference value which corresponds to the vehicle speed, for example, by forming an average value. If the speed of one of the driven wheels deviates from this reference value by a certain percentage, a slippage signal is generated which causes a braking to be applied to the corresponding wheel. If both wheels spin, the engine speed is reduced in addition.